Editing Australopithecus (section)

==Evolution ==
{{Human timeline}}
[[File:Map of the fossil sites of the early hominids (4.4-1M BP).svg|thumb|left|Map of the fossil sites of the early australopithecines in Africa]]
''A. anamensis'' may have descended from or was closely related to ''[[Ardipithecus ramidus]]''.<ref name=Nature573pp214-219>{{cite journal|last1=Haile-Selassie|first1=Yohannes|last2=Melillo|first2=Stephanie M.|last3=Vazzana|first3=Antonino|last4=Benazzi|first4=Stefano|last5=Ryan|first5=Timothy M.|title=A 3.8-million-year-old hominin cranium from Woranso-Mille, Ethiopia|journal=[[Nature (journal)|Nature]]|volume=573|issue=7773|pages=214–219|year=2019|doi=10.1038/s41586-019-1513-8|pmid=31462770|hdl=11585/697577|hdl-access=free|bibcode=2019Natur.573..214H|s2cid=201656331}}</ref> ''A. anamensis'' shows some similarities to both ''Ar. ramidus'' and ''[[Sahelanthropus]]''.<ref name="Nature573pp214-219" />

Australopiths shared several traits with modern apes and humans, and were widespread throughout [[Eastern Africa|Eastern]] and [[Northern Africa]] by 3.5 million years ago (mya). The earliest evidence of fundamentally bipedal hominins is a (3.6 mya) [[Laetoli footprints|fossil trackway in Laetoli]], Tanzania, which bears a remarkable similarity to those of modern humans. The footprints have generally been classified as australopith, as they are the only form of prehuman hominins known to have existed in that region at that time.<ref name=RaichlenEtal1010>{{Cite journal|year=2010 |author=David A. Raichlen |author2=Adam D. Gordon |author3=William E. H. Harcourt-Smith|author4=Adam D. Foster |author5=Wm. Randall Haas Jr |title=Laetoli Footprints Preserve Earliest Direct Evidence of Human-Like Bipedal Biomechanics |journal=[[PLOS ONE]]|pmid=20339543 |volume=5 |issue=3|pmc=2842428 |page= e9769 |doi=10.1371/journal.pone.0009769|editor1-last=Rosenberg|editor1-first=Karen|bibcode=2010PLoSO...5.9769R |doi-access=free }}</ref>

According to the [[Chimpanzee Genome Project]], the [[human–chimpanzee last common ancestor]] existed about five to six million years ago, assuming a constant rate of mutation. However, hominin species dated to earlier than the date could call this into question.<ref name="Bower2006">{{cite journal |author=Bower, Bruce |date=May 20, 2006 |title=Hybrid-Driven Evolution: Genomes show complexity of human-chimp split |journal=[[Science News]] |volume=169 |issue=20 |pages=308–309 |jstor=4019102 |doi=10.2307/4019102}}</ref> ''[[Sahelanthropus tchadensis]]'', commonly called "''Toumai''", is about seven million years old and ''[[Orrorin tugenensis]]'' lived at least six million years ago. Since little is known of them, they remain controversial among scientists since the molecular clock in humans has determined that humans and chimpanzees had a genetic split at least a million years later.{{citation needed|reason=see no evidence this is fixed or agreed by all scientists|date=November 2019}} One theory suggests that the human and chimpanzee lineages diverged somewhat at first, then some populations interbred around one million years after diverging.<ref name="Bower2006" />
<!--As molecular evidence has accumulated, the constant-rate assumption has proven false&mdash;or at least overly general. However, while the molecular clock cannot be blindly assumed to be true, it does hold in many cases, and these can be tested for. For example, molecular clock users are developing workaround solutions using a number of statistical approaches including maximum likelihood techniques and later [[Bayesian modeling]].-->